20. October 2016

Is your building envelope up to par with the latest energy codes?

from Brent Chancellor

The 2016 New York City Energy Conservation code went into effect on October 3rd and is based on the ASHRAE IES 90.1-2013/IECC 2015 code already adopted by Illinois, Maryland, Texas, Alabama, Washington, Vermont and New Jersey.

ASHRAE 90.1 Adoption Map
ASHRAE 90.1 Adoption Map

From ASHRAE IES 90.1-2007 onward, one of the paths to meet the energy code (which was somewhat ambiguous until the 2015 code) has been a continuous insulation requirement for residential and commercial building with mass walls (e.g. concrete). Continuous insulation is defined as:


Insulating material that is continuous across all structural members without thermal bridges other than fasteners and service openings.  It is installed on the interior or exterior or is integral to any opaque surface of the building envelope.


Continuous insulation is also required by ASHRAE IES 90.1 at the roof.  Structural and architectural elements that are affected by these requirements include balconies, exposed slab edges, parapets, canopies, and support structures for rooftop mechanical units.

1325 N Well Street
PHOTO CREDIT: Sedgwick Properties


The requirement of continuous insulation for energy code compliance through the prescriptive path makes structural thermal breaks a necessary consideration for architects and structural engineers. Structural thermal breaks reduce energy loss, improve thermal comfort, and reduce the risk of mold growth by eliminating condensation caused by thermal bridging.

A structural thermal break is a manufactured component that is inserted into a structural member at the point where the structural member crosses the building insulation layer and is in plane with the other insulative sections above and below. For example, structural thermal breaks for concrete balconies are inserted where the balcony slab meets the floor slab and are typically situated in between the window glazing. The thermal break transfers structural loads from the balcony to the floor slab, but drastically reduces energy loss, since it is also an insulator. The insulation material used in Schöck’s Isokorb structural thermal break has a thermal conductivity (k) of that is 90% less than the reinforced concrete slab.

Isokorb type CM


When energy loss through the concrete floor slab is reduced, the floor slab remains at a higher temperature and is more comfortable for the tenant. More importantly, the higher floor slab temperature eliminates the possibility of condensation forming on the interior slab and the associated risk of mold growth.


Concrete balcony WITHOUT structural thermal breaks
Concrete balcony WITHOUT structural thermal breaks


Concrete balcony WITH structural thermal breaks
Concrete balcony WITH structural thermal breaks


Schöck’s Isokorb concrete-to-concrete structural thermal breaks have been delivering worry-free performance for over 30 years.  To learn more about how to meet the continuous insulation requirements of the latest building codes by incorporating structural thermal breaks, give Schöck a call.


Visit the Schöck North America website for more information about structural thermal breaks for concrete and steel connections. Explore the full range of Isokorb® products for balcony, canopy, steel beam, exposed slab edge, parapet and rooftop connections.



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